Put most optimistically, the 11-year-old Yelp is a platform for the public to talk about the organizations that surround them (Even though, like any other form of social media, Yelp reviews have their share of fakes, possibly up to 20%.)

But as University of Michigan social justice scholar Reuben Miller tells Tech Insider, reviews on prisons — as un-intuitive as it might sound — have a number of positive effects, too, from providing vital information on incarcerated life to making these institutions more transparent.

Poor reviews don't just reflect poorly on the space, he says, but also on the people that run it.

In 2015, everybody's invested in brand management.

"If you have a conversation with any warden, a warden's reputation is built on how smoothly they run a prison," Miller says.

Nikos Alexis loads fresh dough into a oven at the Rikers Island jail bakery, which bakes 36,000 loaves of bread weekly to feed the nation's largest jail complex.AP Photo/Bebeto MatthewsIt's not just the wardens. The managers working below them and the elected officials above them all have a stake in how the public perceives their work, he says.

The reviews also create a more open flow of information around prisons and jails, which aren't known for their transparency. As the the Washington Post's Caitlin Dewey reported in 2013, the 1996 Prison Litigation Reform Act made it so that "inmates cannot sue over prison conditions until they have 'exhausted' administrative procedures, and they can ask for only limited changes to prison policy."

"Just a few states, such as Texas and New York, have outside inspectors who watch for abuse within the system," she said.

Miller thinks that the Yelp reviews are part of an on-going trend of the public surveillance of criminal justice actors, similar to the way smartphones seem to constantly be capturing police officers using force on citizens.

"This is all part of a larger movement," Miller says. "State officials and criminal Justice actors are being monitored in a different kind of way, and this could lead to more humane relationships."

The humor makes sense, given the annoyingly cheery tone of the average Yelp critique, but there's valuable information to be communicated in these reviews. They act as a way of passing along institutional knowledge — the secrets that let an inmate better navigate his or her time inside.

In a May 2015 post, Yelp user Jason a. reported on his time in Rikers Island in New York, saying that "I later learned to get a muslim halal card, and a jewish card, and know the kitchen staff to see which card would get me a better meal for the day."

Yelp reviews also help people deal with the pressures of having loved ones in prison. In a recent piece for the Marshall Project, reporter Beth Schwartzapfel tells the story of Victoria Ramos, who went to visit her brother at a California jail but left after she was told that her clothes were too revealing. She checked Yelp and the California Department of Corrections website to see learn about dress codes, but she couldn't find anything.

"Maybe I would have went in the proper attire if I would have read a review similar to mine," she said.

Miller, the University of Michigan associate professor, has spent years researching former inmates in Chicago and Detroit. He says thatwhen people are released from prison, they want to give back.

"It is the sharing of expertise," he says. "There's also families helping families. Here's what happened when my son was arrested. Psychologically it could be a way to voice frustration or gain some glimmer of hope out of an originally negative circumstance, to share in a relatively safe space that's valued by others."